The present invention relates to a system and method for processing spectral information used to aid in the diagnosis of diseased tissue. More particularly, it relates to a method for collecting and displaying the excitation and emission spectra resulting from the laser-induced-fluorescence of tissue.
Methods utilizing the laser-induced-fluorescence ("LIF") of tissue have been developed which permit the characterization of the tissue being examined. This technique has traditionally employed the use of fluorescing agents or dyes which are introduced or applied to the tissue of interest which is then irradiated to induce fluorescence and produce a spectrum that can be used to distinguish diseased from normal tissue. The emission spectra obtained through these methods are normally plotted as intensity versus emission wavelength for a given excitation wavelength. These graphical displays can provide information regarding the diseased condition of tissue as specific peaks in the spectra of abnormal tissue appear which are not present in normal tissue.
Laser catheter systems have also been developed, often in conjunction with known techniques for using fluorescence to aid in diagnosis, for the purpose of inserting a light transmitting device into the human body where laser radiation can be directed onto tissue adjacent the distal end of the catheter to induce fluorescence. The light emitted by the tissue is transmitted along the catheter and analyzed at the proximal end thereof to produce an emission spectrum of the irradiated tissue.
The problem with these standard spectra is that they are highly dependent upon the excitation wavelength that is used such that a highly fragmented view of the spectral characteristics of the tissue is provided. Thus, a more complete method of generating diagnostic information utilizing LIF spectroscopy is needed that more fully characterizes the spectral features of tissue.